Treatment with oestrogen‐receptor agonists or oxytocin in conjunction with exercise protects against myocardial infarction in ovariectomized rats

Abstract

New Findings r What is the central question of this study?Could the activation of oxytocin or oestrogen receptors be protective against myocardial injury after ovariectomy? If so, would exercising have an additional ameliorating effect? r What is the main finding and its importance?The results revealed that when accompanied by exercise, both oestrogen receptor agonists and oxytocin improved cardiac dysfunction, inhibited the generation of pro-inflammatory cytokines and reduced myocardial injury in ovariectomized female rats, suggesting a new approach for protecting postmenopausal women against ischaemia-induced myocardial injury.To investigate the putative protective effects of oxytocin or oestrogen receptor agonists against myocardial injury of ovariectomized sedentary or exercised rats, female Sprague-Dawley rats assigned to sham-operated control and ovariectomized (OVX) groups were kept sedentary or undertook swimming exercise for 4 weeks and were treated with saline, an oestrogen receptor (ER) β (DPN) or ERα agonist (PPT) or oxytocin. Ovariectomy increased weight gain and anxiety in sedentary rats, whereas exercise prevented weight gain. When accompanied by exercise, both ER agonists and oxytocin inhibited weight gain and anxiety; oxytocin, in the absence or presence of exercise, increased the left ventricular diastolic dimensions and ejection fraction, whereas ER agonists also increased left ventricular diameter when given to exercised rats. Upon the induction of myocardial ischaemia-reperfusion in the OVX rats, plasma creatine kinase-(muscle-brain) was depressed by PPT and oxytocin, whereas DPN, PPT and OT reduced plasminogen activator inhibitor-1 concentrations. The increased tumour necrosis factor-α concentration in OVX rats was also suppressed by exercise or DPN, PPT or oxytocin treatments, whereas the interleukin-6 concentration was diminished by all the treatments when given in conjunction with exercise. Disorganization of cardiac muscle fibres was reduced in all exercised rats. Oestrogen receptor agonists, as well as oxytocin, in conjunction with exercise may be effective new therapeutics to protect against myocardial ischaemia in postmenopausal women.

Oestrogen receptor ERα and ERβ agonists ameliorate oxidative brain injury and improve memory dysfunction in rats with an epileptic seizure

“…There is extensive evidence that oestrogens have neuroprotective effects (Ciriza, Carrero, Azcoitia, Lundeen, & Garcia‐Segura, ; Melcangi & Panzica, ; Velíšková, ; Velísková et al., ) and alleviate oxidative stress in several other inflammation models (Kasimay et al., ; Şener, Arbak, Kurtaran, Gedik, & Yeǧen, ). Although the involvement of oestrogen receptors (ERs) in the antioxidant and anti‐inflammatory actions of oestrogens on many other tissues has been studied (Arabacı Tamer et al., ; Bulut et al., ; Kumral, Memi, Ercan, & Yeǧen, ; Özdemir Kumral et al., ), the involvement of oestrogen receptors on seizure‐induced neuronal injury has not been evaluated before.…”

Efeitos do exercício físico na prevenção e tratamento de lesões por isquemia: uma revisão de literatura

“…There is a consensus in the scientific literature that physical exercise is beneficial to the human body, such as, for example, its cardioprotective effects [10][11][12][13] , neuroprotective effects [13][14][15] and improved angiogenesis 16 , however, by detailing each of these benefits and how it is caused, the knowledge is vast, but not complete.…”

Estrogen Therapy Worsens Cardiac Function and Remodeling and Reverses the Effects of Exercise Training After Myocardial Infarction in Ovariectomized Female Rats

“… Saleh et al (2000) demonstrated that acute low-dose use of estradiol leads to improvement in the sensitivity of baroreflex in OVX female rats. In addition, when selective estrogen receptors (ER) agonists and oxytocin are employed in conjunction with swimming training in OVX rats for 4 weeks before the induction of an ischemia and reperfusion protocol, Bulut et al (2016) found improvements in cardiac function and in proinflammatory markers. These results suggest that the activation of ER would be beneficial to protect against myocardial ischemia in post-menopausal women.…”